Advanced option disabled

Hello,
please help me its urgent.. i have my old windows 7 bu ti want to install a clean win 7 ultimate .. but i have this 100MB system reserved file . i cant delete it.. down in option drivers advanced - the delete,extend all options are disabled.. please help me.. i need to delete it not format it...please

am waiting in that screen oly.. please any one help me.. i beg u ..it's really urgent